diff --git a/hal/targets/hal/TARGET_STM/TARGET_STM32F1/serial_api.c b/hal/targets/hal/TARGET_STM/TARGET_STM32F1/serial_api.c
index c7139beeda..bfa025b96e 100644
--- a/hal/targets/hal/TARGET_STM/TARGET_STM32F1/serial_api.c
+++ b/hal/targets/hal/TARGET_STM/TARGET_STM32F1/serial_api.c
@@ -68,7 +68,7 @@ static void init_uart(serial_t *obj)
         UartHandle.Init.Mode = UART_MODE_TX_RX;
     }
 
-        // Fix because HAL_RCC_GetHCLKFreq() don't update anymore SystemCoreClock
+    // Fix because HAL_RCC_GetHCLKFreq() don't update anymore SystemCoreClock
     SystemCoreClockUpdate();
 
     if (HAL_UART_Init(&UartHandle) != HAL_OK) {